Articles for the protection of living tissue

Abstract

An article for the protection of humans, animals and other articles from damage due to undesired exposure to lasers comprising a tubular element comprising at least one layer comprising a xerogel comprising at least one water-insoluble hydrophilic polymer wherein if said tubular element comprises at least three layers the layer adjacent the distal side, relative to the laser beams, of said xerogel layer comprises a metallic layer the proximal surface of which may be reflective or nonreflective of the laser beams and wherein said xerogel layer may further comprise a pigment. In addition, the layer on the distal side of said metallic layer may be a xerogel. During use of the articles of the invention the xerogels thereof are in a hydrated condition, i.e., they are hydrogels.

I claim: 
     
       1. A method for effecting surgery and therapy on humans and animals with lasers without undesired exposure of said humans, animals and other articles to stray laser beams, comprising the steps of (a) inserting a tubular article comprising at least one layer comprising a xerogel comprising at least one hydrophilic water-insoluble polymer, into the body cavity, of said human or animal, wherein said surgery or treatment is to be effected;   (b) applying said laser to the desired site; and   (c) as necessary, adding to said xerogel layer water or an aqueous solution of additive, if any, to replace water lost from said layer during said surgery or treatment; wherein said tubular element may, as desired, be hydrated before or after insertion.   
     
     
       2. The method of claim 1 wherein at least one layer on the side of the first layer opposite the side thereof first impacted by the stray laser beams is a metallic layer. 
     
     
       3. The method of claim 2 wherein said article comprises at least three layers wherein at least one layer on the side of said metal layer opposite the side facing the first xerogel layer comprises a hydrophilic xerogel. 
     
     
       4. The method of claim 3 wherein the surface of the metallic layer on the side of the first xerogel layer has been made nonreflective to laser beams. 
     
     
       5. The method of claim 2 wherein at least one one xerogel layer further comprising at least one pigment is interposed between said first xerogel layer and said metallic layer. 
     
     
       6. The method of claim 5 wherein the surface of the metallic layer on the side of the first xerogel layer has been made nonreflective to laser beams. 
     
     
       7. The method of claim 2 wherein the surface of said metal layer adjacent said first xerogel layer is non-reflective of laser beams. 
     
     
       8. The method of claim 7 further comprising a second hydrophilic xerogel layer interposed between said first xerogel and metallic layers wherein said second xerogel layer further comprises pigments selected from the group consisting of inorganic and organic pigments. 
     
     
       9. The method of claim 8 wherein said pigment is an inorganic pigment selected from the group consisting of TiO 2 , ZnO, the basic white carbonates, sulfates, and silicates of lead, ZnO, lithopone, Sb 2  O 3 , CaCO 3 , silicates of Mg and Al, pyrophillite, bentonite, mica, pumice, BaSO 4 , CaSO 4 , MgO, SiO 2 , diatomite, and powders of Al, Cu, Zn, Pb, Au, Ag, Ni and their alloys, bronzes and Stainless Steel. 
     
     
       10. The method of claim 9 said pigment is TiO 2 . 
     
     
       11. The method of claim 2 wherein said metal is selected from the group consisting of aluminum, titanium, silver, gold and their alloys. 
     
     
       12. The method of claim 11 wherein said metal is aluminum. 
     
     
       13. The method of claim 1 wherein said xerogel layer further comprises at least one pigment. 
     
     
       14. The method of claim 13 wherein the surface of the metallic layer on the side of the first xerogel layer has been made nonreflective to laser beams. 
     
     
       15. The method of claim 1 wherein said tubular element comprises at least two layers wherein the first layer, which is the first layer to be struck by the stray laser beams, comprises said xerogel. 
     
     
       16. The method of claim 15 wherein said first layer further comprises at least one pigment. 
     
     
       17. The method of claim 16 wherein the surface of the metallic layer on the side of the first xerogel layer has been made nonreflective to laser beams. 
     
     
       18. The method of claim 1 wherein at least one of said xerogel layers comprises at least one additive selected from the group consisting of pharmaceutically acceptable salts, colorants and, pigment medications. 
     
     
       19. The method of claim 1 wherein the hydrophilic water-insoluble polymer is selected from the group consisting of poly(ethylene oxide)s and copolymers of acrylonitrile with acrylamide. 
     
     
       20. The method of claim 19 wherein said polymer is a poly(ethylene oxide). 
     
     
       21. The method of claim 19 wherein said polymer is a poly(acrylonitrile-co-acrylamide).